1999 MITSUBISHI LANCER EVOLUTION VI service

52B-1
SUPPLEMENTAL
RESTRAINT
SYSTEM (SRS)
CONTENTS
GENERAL INFORMATION 2. . . . . . . . . . . . . . . .
SRS SERVICE PRECAUTIONS 3. . . . . . . . . . .
SPECIAL TOOLS 5. . . . . . . . . . . . . . . . . . . . . . . .
TEST EQUIPMENT 5. . . . . . . . . . . . . . . . . . . . . .
TROUBLESHOOTING 6. . . . . . . . . . . . . . . . . . . .
SRS MAINTENANCE 15. . . . . . . . . . . . . . . . . . .
POST-COLLISION DIAGNOSIS 19. . . . . . . . .
INDIVIDUAL COMPONENT SERVICE 22. . . WARNING/CAUTION LABELS 23. . . . . . . . . .
SRS AIR BAG CONTROL UNIT
(SRS-ECU) 24. . . . . . . . . . . . . . . . . . . . . . . . . . . .
AIR BAG MODULES AND CLOCK
SPRING 25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AIR BAG MODULE DISPOSAL
PROCEDURES 32. . . . . . . . . . . . . . . . . . . . . . . .
Undeployed Air Bag Module Disposal
Procedures 32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deployed Air Bag Module Disposal
Procedures 40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CAUTION

Carefully read and observe the information in the SERVICE PRECAUTIONS (P.52B-3.) prior to any service.

For information concerning troubleshooting or maintenance, always observe the procedures in the Troubleshooting
(P.52B-6.) section.

If any SRS components are removed or replaced in connection with any service procedures, be sure to follow the
procedures in the INDIVIDUAL COMPONENT SERVICE section (P.52B-22.) for the components involved.

If you have any questions about the SRS, please contact your local distributor.

SRS – General Information52B-2
GENERAL INFORMATION
To improve safety, the SRS is available as optional
part.
The SRS consists of two air bag modules, SRS
air bag control unit (SRS-ECU), SRS warning lamp
and clock spring. One air bag is located in the
centre of the steering wheel and another above
the glove box. Each air bag has a folded air bag
and an inflator unit. The control unit under the floor
console monitors the system and has a safing G
sensor and an analog G sensor. The warning lamp
on the instrument panel indicates the operationalstatus of the SRS. The clock spring is installed
in the steering column.
Only authorized service personnel should do work
on or around the SRS components. Those service
personnel should read this manual carefully before
staring any such work. Extreme care must be used
when servicing the SRS to avoid injury to the service
personnel (by inadvertent deployment of the air
bags) or the driver (by rendering the SRS
inoperative).
Air bag module
(Driver’s side)Clock springAir bag module
(Front passenger’s side)
Diagnosis
connector
SRS-ECU
SRS warning lamp

SRS – SRS Service Precautions52B-3
SRS SERVICE PRECAUTIONS
1. In order to avoid injury to yourself or others
from accidental deployment of the air bag during
servicing, read and carefully follow all the
precautions and procedures described in this
manual.
2. Do not use any electrical test equipment on
or near SRS components, except those
specified on P.52B-5.
3. Never Attempt to Repair the Following
Components:

SRS air bag control unit (SRS-ECU)

Clock Spring

Air Bag Module
(Driver‘s side or front passenger’s side*)NOTE
*: Vehicles with front passenger’s air bag
If any of these components are diagnosed as
faulty, they should only be replaced, in
accordance with the INDIVIDUAL COM-
PONENT SERVICE procedures in this manual,
starting at page 52B-22.
4. After disconnecting the battery cable, wait 60 seconds
or more before proceeding with the following work.
The SRS system is designed to retain enough voltage
to deploy the air bag for a short time even after the
battery has been disconnected, so serious injury may
result from unintended air bag deployment if work
is done on the SRS system immediately after the
battery cables are disconnected.
5. Do not attempt to repair the wiring harness connectors
of the SRS. If any of the connectors are diagnosed as
faulty, replace the wiring harness. If the wires are
diagnosed as faulty, replace or repair the wiring harness
according to the following table.
Battery Insulating tape
SRS-ECU connector

SRS – SRS Service Precautions52B-4
SRS-ECU
terminal No.Harness connector
(No. of terminals,
colour)Destination of harnessCorrective action
1 to 421 pins, yellow––
5Body wiring harness → Clock spring → Air bag
module (Driver’s side)
Correct or replace each
wiring harness Replace
6
module (Driver’s side)wiring harness. Replace
clock spring.
7*Body wiring harness → Air bag module (Front
passenger’s side)
Correct or replace each
wiring harness
8*
passenger’s side)wiring harness.
9,10––
11Body wiring harness → Diagnosis connectorCorrect or replace each
wiring harness.
12––
13Body wiring harness → Junction block (fuse No.2)Correct or replace each
wiring harness
14Body wiring harness → Junction block (fuse No.4)
wiring harness.
15Body wiring harness → SRS warning lamp
16 to 19––
20Body wiring harness → EarthCorrect or replace each
wiring harness.
21––
NOTE
*: Vehicles with front passenger’s air bag
6. SRS components should not be subjected to hear over 93C, so remove the SRS-ECU, air bag
module and clock spring before drying or baking the vehicle after painting.
7. Whenever you finish servicing the SRS, check warning lamp operation to make sure that the system
functions properly. (Refer to P.52B-14.)
8. Make certain that the ignition switch is LOCK (OFF) position when the MUT-II is connected or
disconnected.
9. If you have any questions about the SRS, please contact your local distributor.
NOTE
SERIOUS INJURY CAN RESULT FROM UNINTENDED AIR BAG DEPLOYMENT, SO USE ONLY
THE PROCEDURES AND EQUIPMENT SPECIFIED IN THIS MANUAL.

SRS – Troubleshooting52B-6
TROUBLESHOOTING
STANDARD FLOW OF DIAGNOSTIC TROUBLESHOOTING
Refer to GROUP 00 – How to Use Troubleshooting/Inspection Service Points.
DIAGNOSIS FUNCTION
DIAGNOSIS CODES CHECK
Connect the MUT-II to the diagnosis connector (16-pin) under the instrument under cover, then check
diagnosis codes.
(Refer to GROUP 00 – How to Use Troubleshooting/Inspection Service Points.)
ERASING DIAGNOSIS CODES
Connect the MUT-II to the diagnosis connector and erase the diagnosis code.
Caution
Turn off the ignition switch before connecting or disconnecting the MUT-II.
INSPECTION CHART FOR DIAGNOSIS CODES
Inspect according to the inspection chart that is appropriate for the malfunction code.
Code No.Diagnosis itemReference page
14Analog G-sensor system in the SRS-ECU52B-7
15,16Safing G-sensor system in the SRS-ECU52B-7
21, 22, 61, 62Driver’s side air bag module (squib) system52B-8
24, 25, 64, 65Front passenger’s side air bag module (squib) system52B-9
31, 32SRS-ECU capacitor system52B-9
34*Connector lock system52B-10
35SRS-ECU (deployed air bag) system52B-10
41*IG1 (A) power circuit system52B-10
42*IG1 (B) power circuit system52B-11
43SRS warning lamp drive circuit
system
Lamp does not illuminate.*52B-12
systemLamp does not switch off.52B-12
44SRS warning lamp drive circuit system52B-13
45SRS-ECU non-volatile memory (EEPROM) and A/D converter system52B-13
51, 52Driver’s side air bag module (squib ignition drive circuit) system52B-13
54, 55Front passenger’s side air bag module (squib ignition drive circuit) system52B-13
NOTE
(1) *: If the vehicle condition returns to normal, the diagnosis code will be automatically erased, and the SRS warning
lamp will return to normal.
(2) If the vehicle has a discharged battery it will store the fault codes 41 or 42. When these diagnosis codes are
displayed, check the battery.

SRS – Post-collision Diagnosis52B-19
POST-COLLISION DIAGNOSIS
To inspect and service the SRS after a collision (whether
or not the air bags have deployed), perform the following
steps.
SRS-ECU MEMORY CHECK
1. Connect the MUT-II to the diagnosis connector (16-pin).
Caution
Make certain that the ignition switch is OFF when
the MUT-II is connected or disconnected.
2. Read (and write down) all displayed diagnosis codes.
(Refer to P.52B-6.)
NOTE
If the battery power supply has been disconnected or
disrupted by the collision, the MUT-II cannot communicate
with the SRS-ECU. Inspect and, if necessary, repair the
body wiring harness before proceeding further.
3. Read the data list (fault duration and how many times
memories are erased) using the MUT-II.
Data list
NoService Data ItemApplicability
92Number indicating houw often the memory is clearedMaximum time to be stored: 250
93How long a problem has lasted (How long it takes
from the occurrence of the problem till the first igniting
signal)Maximum time to be stored: 9,999 minutes
(approximately 7 days)
94How long a problem has lasted (How long it takes
from the first igniting signal till now)
4. Erase the diagnosis codes and after waiting 5 seconds
or more read (and write down) all displayed diagnosis
codes. (Refer to P.52B-6.)

SRS – Post-collision Diagnosis52B-20
REPAIR PROCEDURE
WHEN AIR BAG DEPLOYS IN A COLLISION.
1. Replace the following parts with new ones.

SRS-ECU (Refer to P.52B-24.)

Air bag module (Refer to P.52B-25.)
2. Check the following parts and replace if there are any
malfunctions.

Clock spring (Refer to P.52B-25.)

Steering wheel, steering column and intermediate
joint
(1) Check wiring harness (built into steering wheel)
and connectors for damage, and terminals for
deformation.
(2) Install air bag module to check fit or alignment
with steering wheel.
(3) Check steering wheel for noise, binds or difficult
operation and excessive free play.
3. Check harnesses for binding, connectors for damage,
poor connections, and terminals for deformation.
(Refer to P.52B-18.)
WHEN AIR BAG DOES NOT DEPLOY IN LOW-SPEED
COLLISION.
Check the SRS components. If the SRS components are
showing any visible damage such as dents, cracks, or
deformation, replace them with new ones. Concerning parts
removed for inspection, replacement with new parts and
cautionary points for working, refer to appropriate INDIVIDUAL
COMPONENT SERVICE, P.52B-22.

SRS – Post-collision Diagnosis / Individual Component Service52B-22
Steering wheel, steering column and intermediate joint
1. Check wiring harness (built into steering wheel) and
connectors for damage, and terminals for deformation.
2. Install air bag module to check fit or alignment with steering
wheel.
3. Check steering wheel for noise, binds or difficult operation
and excessive free play.
Harness connector (body wiring harness)
Check harnesses for binding, connectors for damage, poor
connection, and terminals for deformation. (Refer to P.52B-18.)
INDIVIDUAL COMPONENT SERVICE
If the SRS components are to be removed or replaced as a result of maintenance, troubleshooting,
etc., follow each procedure (P.52B-24 – P.52B-31)
Caution
1. SRS components should not be subjected to hear over 93C, so remove the SRS-ECU, air
bag module and clock spring before drying or baking the vehicle after painting.
Recheck SRS system operability after re-installing them.
2. If the SRS components are removed for the purpose of check, sheet metal repair, painting,
etc., they should be stored in a clean, dry place until they are reinstalled.